In general, a washstand has a drain system to discharge water from a basin to a drain or the like. Korea Utility Model Publication No 20-0459796 (Apr. 25, 2012) discloses a drain system for a washstand. FIG. 1 is a cross-sectional view illustrating the drain system for the washstand according to the related art.
As illustrated in FIG. 1, the drain system for the washstand according to the related art includes a pop-up drain 10, a hose 20, and a drain pipe 30. A basin 1 is a container with an opened top to store water therein, and is provided with a through-hole in a center portion thereof, and a pop-up valve of the pop-up drain 10 is provided in the through-hole. The hose 20 is made of a flexible tube, and the drain pipe 30 is made of a metal tube, such as stainless steel, in order to connect the hose 20 and the drain 3. However, the drain system for the washstand according to the related art which is illustrated in FIG. 1 has problems in that since durability of the hose 20 is weak, the hose is easily broken, and in that the drain system is configured to give off a bad smell. Therefore, it is a recent trend to replace the whole drain pipe by a metallic material.
FIG. 2 is a cross-sectional view illustrating a drain pipe assembly for installation of a washstand according to the related art. As illustrated in FIG. 2, a drain pipe 2 is installed to the through-hole provided in a base of the basin 1, and an upper end of the drain is provided with a rim 21 that extends outwardly in a radial direction, so that the drain pipe 2 is supported by the top surface of the base of the basin 1. A packing member 22 is interposed between the rim 21 and the top surface of the base of the basin 1. Also, the drain pipe 2 is fastened to the bottom surface of the base of the basin 1 by a nut 24, and thus the drain pipe 2 is engaged to the basin 1. A packing member 22 and a washer 23 are, interposed between the nut 24 and the bottom surface of the base of the basin 1. A lower end of the drain pipe 2 is coupled to a trapping pipe 4 with a bent flow path in order to prevent gases or bad smells from being flowing backward, or alien matters or bugs from coming in.
Explaining the method of assembling and disassembling the drain pipe assembly for instillation of the washstand according to the related art, the drain pipe 2 is firstly inserted into the through-hole formed in the base of the basin 1 from an upward direction to a downward direction, the lower end of the drain pipe 2 is coupled to the upper end of the trapping pipe 4, and then the drain pipe 2 is fixed to the basin 1 by fastening the nut 24. When the drain pipe 2 is disassembled, the nut 24 is unfastened, the lower end of the drain pipe 2 is released from the upper end of the trapping pipe 4, and then the drain pipe 2 is withdrawn from the through-hole formed in the base of the basin 2, thereby completing the disassembling work.
However, the drain pipe assembly for installation of the washstand according to the related art has problems in that a special tool is required to fasten or unfasten the nut when the drain pipe is assembled or disassembled; replacing and repairing work is inconvenience, and a lot of working hours are needed.